Door operating mechanism

ABSTRACT

This invention relates to a railroad hopper door operating mechanism which incorporates a reciprocating scissor drive in opening and closing railway car hopper doors. In particular, the mechanism utilizes a manually operated scissors link means which converts rotation of a transverse reversely threaded shaft into longitudinal movement of an input drive link which through a lost motion connection transmits forces to the output drive link to the door operating levers for opening and closing of the hopper car doors and yet isolates damaging forces from the scissors link means. The input drive versus output drive construction produces a force couple arrangement to inhibit accidental opening of the doors.

United States Patent Schuller [4 July 1 1, 1972 [54] DOOR OPERATING MECHANISM Primary Examiner-Allen N. Knowles [72] sdwlk" Attorney-Hilmond 0. Vogel and Wayne Morris Russell [73] Assignee: Pullman Incorporated, Chicago, Ill.

57 ABSTRACT [22] Filed: Dec. 12, 1969 l l I l h This invention re ates to a rai road opper door operating [2 l 1 p 884,424 mechanism which incorporates a reciprocating scissor drive in opening and closing railway car hopper doors. In particular, 52 0.5. CI 105/240, 105/251. 105/290. mechanism "miles a manually link 105/307 means which converts rotation of a transverse reversely [5 I] Int. Cl. ..B6ll 9/00 lhreadcd shaft into longitudinal movement of an input drive [58] Field of Search "105/240 289 290 307 25' link which through a lost motion connection transmits forces i to the output drive link to the door operating levers for opening and closing of the hopper car doors and yet isolates [56] Relennm cued damaging forces from the scissors link means. The input drive UMTED STATES PATENTS versus output drive construction produces a force couple ar- 3 40] 644 9/1968 C 105/245 x rangement to inhibit accidental opening of the doors.

npe 3,543,691 12/1970 Nagy 105/290 X Claims, 5 Drawing figures PATENTEU JUL Y 1 I972 SHEET 1 [1F 2 INVENTOR JAMES J. SCHULLER ATT'Y noon orsmrmo MECHANISM SUMMARY The object of the invention is to provide an improved manual door operating mechanism for use in railway hopper cars. The mechanism of this invention has an advantage of alv lowing rapid and complete opening of the hopper car doors after a predetermined movement of the operating mechanism. Generally manual door operating mechanisms open the hopper car doors at a slow and constant rate. The disadvantage of this is that once the doors reach a certain position the weight of the lading will force the doors open and in turn pull on the operating mechanism. This damages the manual door operating mechanism. The present invention releases the doors rapidly and allows them to open completely under the weight of the lading without pulling or having any other adverse or damaging effects on the manual door operating mechanism. The operation of the mechanism is essentially that of a scissors-type mechanism. A drive shaft extends transversely through the hopper car at both ends and is accessible from either side of the car. Rotation of this drive shaft by hand or by a suitable power assistance is transmitted through a speed reducer to rotate a reversely threaded shafi which drives the scissors links of the mechanism. This shafi is rotated much slower than the drive shaft but with a greater torque. Rotation of this reversely threaded transverse shaft is converted into longitudinal movement of a drive link which supplies forces to the door operating levers for opening and closing of the hopper car doors. Upon initial rotation of this drive shaft to open doors there is a delay in door opening during which time a slack is induced into the door opening linkage mechanism so that when the hopper doors do begin opening sudden jarring will be prevented from jolting the mechanism; when sudden opening of the massive doors occurs, the lost motion connection between the input and output drive portions of the door operating mechanism provides a slack which prevents damaging forces from being transmitted to the input drive portion of the door operating mechanism. The door operating mechanism is also designed to resist buff and draft forces that would tend to open the doors accidently.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the railway hopper car showing the location of the manual door operating mechanisms located at each end of the car;

FIG. 2 is an enlarged partial side elevational section view of the manual door operating mechanism shown in the inoperative position (hopper doors closed) and depicting its location relative to the door operating levers;

FIG. 3 is a top view of the mechanism as illustrated in FIG.

FIG. 4 illustrates a touching position between the force transmitting member of the mechanism and a drive lever of the door operating lever mechanism; and

FIG. 5 illustrates the relative position of the force transmitting member and the drive lever of FIG. 4 when the hopper car doors are fully open.

DETAILED DESCRIPTION With reference now to the drawings and in particular with reference to FIG. I there is shown a railway car having wheels 11 riding on rails 11 with hoppers 13 having hopper car doors 14 which are operatively connected with the first door operating drive lever 15 and second door operating lever 15a. A center sill 16 extends longitudinally the length of the car and has the manual door operating mechanisms 17 of this invention located at each end; also, the horizontal center line of the center sill defines the longitudinal center line 18 (FIG. 2) of the railway hopper car 10.

Referring now to FIGS. 2 and 3, the invention is illustrated as positioned in a railway hopper car and in particular displays the positioning of the mechanism utilized at the right end of the hopper car 10 illustrated in FIG. 1. Drive shafts l9 and 19a extend transversely across the hopper car 10 thus making operation of the mechanism possible from either side of the car. The drive shafts l9 and are ooupably connected to the speed reducer 22 by means of the couplers 19b and He. The drive shafts 19, 19a are mounted in bearings 21 and have sockets 20 at their uncoupled ends.

A speed reducer 22 is displaced transversely from the longitudinal center line 18 of the hopper car It) to facilitate a connection between the drive shafts l9 and 19a and the reversely threaded shaft 25. The speed reducer 22 is a commercial type with a three to one reduction ratio. Supporting this speed reducer 22 is a mounting means 23 which is U-shaped having its vertical legs 23 extending from the deck 57 to the bottom of the speed reducer and then joining in a horizontal plane to form the bottom support for the speed reducer 22.

The output shaft 24 of the speed reducer 22 is joined to the reversely threaded shaft 25 by the coupler 19c. The reversely threaded shaft 25 is mounted in bearings 21a which are mounted in the bearing mounting means 21b. The bearing mounting means are vertical plates extending from the car deck 57 and permanently affixed thereto having openings at their upper ends to accommodate the bearings 21a and consequently support the reversely threaded shaft 25.

The reversely threaded shaft 25 comprises two threaded portions, one with a right hand thread and the other with left hand thread. The ends of the threaded shaft 25 are stepped to accommodate a bearing of smaller diameter than the outside diameter of the threaded portions; this is done to provide a bearing surface at the shafi ends and to provide a means for easily threading the suitably threaded nuts 26 and 26a onto the shaft 25. The nuts 26 and 260 are pivotally connected at 27 and 27a to the scissors links 29. The scissors links extend from pivots 27 and 27a and are joined at 28 which is a common pivot means.

Referring to FIG. 2 and in particular to the scissors links 29 of the manual door operating mechanism 17 it is noted that the scissors links 29 include offset links 30 combined with straight links 31 and joined together by a vertically extending connecting plate 32. The offset links 30 and the straight link 31 are used in unison so that the offset in one link will provide clearance for movement of the straight link 31 of the other scissors link 29. The common pivot means 28 of the scissors link 29 includes a pivot pin 33 extending vertically through to adjacent and in-line openings of members 30 and 31 of the scissors links 29 and through an in-line opening 37a of the drive link 34.

The drive link 34 includes a pipe 35 having a cover plate 36 over one end and a nose member 43 covering the opposite end. Attached to the cover plate 36 is a pivot connecting means 37 having an opening 374: for connection with the pivot pin 33. The drive link 34 is supported by a supporting bracket 38 fixedly attached to the top of the car deck 57 and includes a vertical transverse plate 39 having two fixedly attached spaced supports 40. The upper end of the supporting bracket 38 contains a pipe section 41 which accommodates the drive link 34. The nose member 43 contains a pivot pin 47 which extends transversely through its body and provides a means for attaching the first clevis 48. Also the nose has an arcuate end The first clevis 48 has a chain link 49 attached to it with the chain link attached to a second clevis 50 which is pivotally connected to the drive lever 52 by means of the second clevis pin 51.

The auxiliary drive lever 52 (for additional force multiplication) has an angled comer 53 to accommodate efficient force transmission from the nose member 43 to the lever 52. The fulcrum 54 is at the lower end of the drive lever 52 and includes a lever pivot pin 55 which extends through an opening in the lever 52 and through openings in the fulcrum mounting means 56 which is fixedly attached to the car deck 57. Between the second clevis pin 51 and the lever pivot pin 55 is pivotally attached a connecting drive member 58a which transmits forces from the drive lever 52 to the further force multiplier door operating lever 15. The connecting member 580 is essentially a pipe having its ends enclosed by the cover plates 61b to which are fixedly attached longitudinally extending connecting plates 59 which have openings for accommodating pivot pins 63 and 64.

The door operating levers 15 function in the same manner as those described in co-pending application Ser. No. 884,535 by W. R. Shaver and E. J. Nagy filed the same date as this application now US. Pat. No. 3,633,515 issued Jan. ll, I972, the Shaver and Nagy application being herein incorporated by reference.

The longitudinally extending connecting members or force transmitting means 58 connect the door operating levers l5 and a and comprise a larger pipe section 60 fixedly attached to a smaller pipe section 60a which has a cover plate 61a over its open end. Affixed to the cover plate 61a are longitudinally extending connecting plates 590 which have openings adjacent the lower opening of the drive lever 15 for insertion of a pivot pin 62 to define a pivotal connection.

THE OPERATION Referring now to the drawings and in particular to FIG. 2, the mechanism 17 is illustrated in the inoperative position with the hopper car doors l4 closed. By means of the drive shafts l9 and 190 the speed reducer 22 is accessible for rotation from either side of the hopper car 10. Rotation of the drive shafts I9 and 19a is accomplished by insertion of a suitably shaped member into the sockets 20 and consequent rotation by hand or by other drive means. This rotation of the drive shaft I9 is transmitted through the speed reducer 22 which reduces the rotational speed by a ratio of 3 to l, which is, three rotations of the drive shaft 19 or 19a results in one rotation of the output shaft 24 of the speed reducer 22. Rotation of the output shaft 24 results in an identical rotation of the reversely threaded shaft 25. The rotation of the reversely threaded shaft 25 upon door opening will result in movement of the suitably threaded nuts 26 and 26a toward the longitudinal center line 18 of the hopper car 10. This transverse movement of the nuts 26 and 26a causes a longitudinal movement of the common pivot means 28 which is caused by the links 29 which move in both translation and rotation to convert the transverse movement of the nuts 26 and 26a into a longitudinal movement of the common pivot means 28 (See FIG. 3). Longitudinal movement of the common pivot means 28 results in a similar longitudinal movement of the drive link 34 which is pivotally connected at one end to the common pivot means 28.

Referring now to FIG. 2 4 and 5, it is noticed that when the drive link 34 together with its nose member 43 move longitudinally toward the angled corner 53 of the drive lever 52 the clevis and chain link members 48, 49 and 50, will have slack induced since the drive lever 52 remains stationary. When the slack is induced these three members 48, 49 and 50 (which form a lost motion connection) drop out of the way in preparation for contact between the arcuate end 44 of the nose member 43 and the angled comer 53 of drive lever 52. As is shown in the co-pending patent application Ser. No. 777,430, filed Nov. 20, I968 to Herman A. Aquino, now US. Pat. No. 3,596,608 issued Aug. 3, 197i, and incorporated herein by reference thereto, the connections between the levers I5, I54 and door arms 15b provide a self locking feature or locked over center position when the doors 14 are closed. Because of the self-locking feature of the hopper doors l4 and the door operating levers l5 and 150 when the hopper doors are in a fully closed position weight of the lading on the doors will tend to rotate the door operating lever 15 illustrated in FIG. 2 in a clockwise direction. This rotation of lever 15 is prevented, however, by restraining members (center sill mounted fulcrum stop 70 and right roller housing stop 71 in housing 72) thus restricting the lever connecting member 580 and the drive lever 52 in the position illustrated in FIG. 2 until movement of drive lever 52 is initiated through contact of the nose drive member or plunger 43. Contact between the nose or trip member 43 and the angled corner 53 of the drive lever 52 will rotate the drive lever 52 about the lever pivot pin 55 which acts as the fulcrum 54 of the drive lever 52. Rotation of the drive lever 52 continues until the second clevis pin 51 is approximately above the lever pivot pin 55 (see FIG. 4). At this point said self-locking or over center lock feature of the hopper doors 14 has been eliminated and the door operating levers l5 and are in an over-center unlocked position at which point the weight of the lading will force open the hopper car doors 14 very rapidly. This rapid opening of the doors results in an accompanying rapid movement of the door operating lever 15 illustrated in FIG. 2 from the position illustrated by solid lines to the position illustrated by dotted lines. This movement of the door operating lever 15 results in a rapid longitudinal movement of the lever connecting member 580 and a rapid rotation of the drive lever 52. The shifting from first fulcrum 70 to housing stop or second fulcrum 73 provides the necessary leverage to vary the load applied in opening the doors as disclosed by the aforesaid Shaver and Nagy application. This rapid movement results in a termination of contact between the nose member 43 and the angled comer 53 of the drive lever 52 which results in positioning of the two members as illustrated in FIG. 5. It is noticed that this rapid separation of the surfaces of 53 and 43 takes up the slack in the connecting members 48, 49 and 50 without pulling on the clevis pivot pin 47 which would pull the drive link 34, the scissors links 29, and which would tend to bend the reversely threaded shaft 25.

To close the hopper car doors l4 a reverse rotation is ap plied to the drive shafts 19 or 19a which also rotates the reversely threaded shaft with a 3 to 1 reduction and moves the suitably threaded nuts 26 and 26a away from the longitudinal center line 18 resulting in a longitudinal movement of the common pivot means 28 towards the reversely threaded shaft 25. This movement of the pivot means 28 also moves the drive link 34 and the nose member 43 which in turn through these members 48, 49 and 50 will pull the drive lever 52 toward the reversely threaded shaft 25 until the drive lever 15 as illustrated in FIG. 2 has reached the limits of its rotation. When this occurs the hopper car doors 14 are closed and in an overcenter or self-locked position. Because the power source 17 with its force transmitting means 52, 58a, and the lever connecting member 58 are on opposite ends of the movable pivot lever 15 the inertial force couples which these opposed members generate because of buff and draft forces on the car will more or less cancel each other thus preventing unintentional hopper door opening upon sudden impact.

The foregoing description and drawings are given merely to explain and illustrate the invention and the invention is not to be limited thereto, except insofar as the appended claims are so limited, since those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.

What is claimed is:

I. In a hopper car having a pair of pivoted hopper doors, a mechanism for opening and closing said doors comprising:

lever means for applying a mechanical power advantage to the doors to open same,

drive link means being reciprocably mounted for movement in a longitudinal direction and operatively connected with the lever means for operation thereof,

scissors mechanism operatively connected with said drive link means for reciprocating the latter,

rotatable reversely flireaded shaft means operatively connected with and operative upon said scissors mechanism for extending and collapsing same to reciprocate the drive link means,

said scissors mechanism converting rotation of said reversely threaded shaft means into longitudinal movement of the drive link means to operate said lever means to open and close the hopper car doors.

2. The invention according to claim I, and

said reversely threaded shah means extending transversely of the hopper car and said scissors mechanism having a pair of scissor links moving on the shaft means and toward and away from one another links in response to a rotation of said shaft means, said pair of links having one of their ends pivotally joined together in common connection with the drive link means and having the other of their ends pivotally connected to the shaft means in linearly constrained movement along the shaft means.

3. The invention according to claim 1 and said drive link means being in the path of the lever means for movement of the lever means by contact with the drive link means, and

a flexible linkage being connected between the drive link means and the lever means, said flexible linkage permitting a lost motion movement of said drive link means upon initial operation of the scissors mechanism during which time slack is induced into said linkage, movement of said lever means being delayed until termination of the lost motion movement of said drive link means resulting in delayed contact between said drive link means and the lever means for movement of the lever means.

4. The invention according to claim 1, and

said lever means including a mechanical power multiplier auxiliary drive lever member connecting with the drive link means and said lever means including a series of vertically extending longitudinally spaced door operating levers, said longitudinally spaced levers having pivoted arms extending therefrom and adapted for pivotal connection with the hopper doors, said arms being in an overcenter locked configuration when the hopper doors are closed.

5. The invention according to claim 1, and

said lever means including a first drive lever member and first and second fulcrums spaced vertically from one another and selectively engageable with the drive lever member for pivotal movement of the lever member about the selected fulcrum to vary the length of the moment arm of the lever member to operate either at a high mechanical power advantage or at a high speed movement for fast opening of the hopper doors.

6. In a hopper car having a pair of pivoted hopper doors, a

door operating lever mechanism for opening and closing said doors comprising:

a lever assembly including longitudinally spaced lever members and a connecting drive member,

said lever assembly comprising a longitudinally extending force transmitting means and first lever means having upper portions pivotally connected with said connecting drive member and having lower portions connecting with said force transmitting means,

second lever means having upper portions pivotally connected to the vehicle and having lower portions connecting with said force transmitting means,

door arm means pivotally connected with the doors and to the lower portions of said first and second lever means, and

lever pivot means being mounted on the car and connecting with each of the first and second lever means for accommodating pivotal movement thereof,

the buff and draft forces developed in the force transmitting means being offset by the forces developed in the connecting drive member.

7. The invention according to claim 6, and

a fixed fulcrum member mounted on the car below the pivot means of the first lever means, said first lever means in pivoting between outboard and inboard direction being fulcrumed about the fulcrum member whereby a high mechanical power moment arm is developed between the drive means moving the first lever means upon initial opening of the door means and whereby when the door arm means moves past center to the door unlocking position, the first lever means fulcrums about its pivot means to develop a longer moment arm between the door arm means and the pivot means of the first lever means for quick travel gravity opening of the door means. 8. A hopper car having pivoted hopper doors and a 5 mechanism for opening and closing said doors comprising:

longitudinally spaced lever means for applying a mechanical power advantage to the doors to open same,

drive link means being reciprocally mounted for movement in a longitudinal direction and operatively connected with said lever means for operation thereof,

linkage operating means operatively connected with said drive link means for reciprocating the latter, and

longitudinally extending force transmitting means being connected with said lever means and being connected with said hopper doors and being spaced below said drive link means whereby forces developed in the force transmitting means would be offset by forces developed in the drive link means.

9. The invention according to claim 8, and

said linkage operating means comprising a scissors mechanism operatively connected with said drive link means for reciprocating the latter and a rotatable reversely threaded shafi means being operatively connected with and operative upon said scissors mechanism for extending and collapsing same to reciprocate the drive means.

10. The invention according to claim 8, and

lost motion connection means connecting with said lever means and with said drive link means permitting lost motion movement of the drive link means upon initial operation of the linkage operating means resulting in delayed contact between the drive link means and the lever means for movement of the lever means.

I l. The invention according to claim 8, and

said linkage operating means comprising extendable means operatively connected with the drive link means and extendable in a longitudinal direction for moving the drive link means in a longitudinal direction, and threaded shaft means for contracting and expanding such extendable means being operatively connected with and operative upon said extendable means attendant to movement of said drive link means.

12. A hopper car having pivoted hopper doors and a mechanism for opening and closing said doors comprising:

longitudinally spaced lever means for applying a mechanical power advantage to the doors to open same,

drive link means being reciprocally mounted for movement in a longitudinal direction and operatively connected with said lever means for operation thereof,

linkage operating means operatively connected with said drive link means for reciprocating the latter, and

lost motion connection means connecting with said lever means and with said drive link means permitting lost motion movement of the drive link means upon initial operation of the linkage operating means resulting in delayed contact between the drive link means and the lever means for movement of the lever means.

13. The invention according to claim 12, and

said lever means including a first lever member connected with said drive link means and a second lever member connected with said first lever member, said second lever member multiplying the mechanical effect of the first lever member and the first lever member multiplying the mechanical effect of the drive link means.

14. The invention according to claim 13, and

said second lever member including first and second fulcrums spaced vertically from one another and selectively engageable with the second lever member for pivotal movement of the second lever member about the selected fulcrum to vary the length of the moment arm of the second lever member to operate either at a high mechanical power advantage or at a high speed movement for fast opening of the hopper doors.

* R t i 

1. In a hopper car having a pair of pivoted hopper doors, a mechanism for opening and closing said doors comprising: lever means for applying a mechanical power advantage to the doors to open same, drive link means being reciprocably mounted for movement in a longitudinal direction and operatively connected with the lever means for operation thereof, scissors mechanism operatively connected with said drive link means for reciprocating the latter, rotatable reversely threaded shaft means operatively connected with and operative upon said scissors mechanism for extending and collapsing same to reciprocate the drive link means, said scissors mechanism converting rotation of said reversely threaded shaft means into longitudinal movement of the drive link means to operate said lever means to open and close the hopper car doors.
 2. The invention according to claim 1, and said reversely threaded shaft means extending transversely of the hopper car and said scissors mechanism having a pair of scissor links moving on the shaft means and toward and away from one another links in response to a rotation of said shaft means, said pair of links having one of their ends pivotally joined together in common connection with the drive link means and having the other of their ends pivotally connected to the shaft means in linearly constrained movement along the shaft means.
 3. The invention according to claim 1, and said drive link means being in the path of the lever means for movement of the lever means by contact with the drive link means, and a flexible linkage being connected between the drive link means and the lever means, said flexible linkage permitting a lost motion movement of said drive link means upon initial operation of the scissors mechanism during which time slack is induced into said linkage, movement of said lever means being delayed until termination of the lost motion movement of said drive link means resulting in delayed contact between said drive link means and the lever means for movement of the lever means.
 4. The invention according to claim 1, and said lever means including a mechanical power multiplier auxiliary drive lever member connecting with the drive link means and said lever means including a series of vertically extending longitudinally spaced door operating levers, said longitudinally spaced levers having pivoted arms extending therefrom and adapted for pivotal connection with the hopper doors, said arms being in an over-center locked configuration when the hopper doors are closed.
 5. The invention according to claim 1, and said lever means including a first drive lever member and first and second fulcrums spaced vertically from one another and selectively engageable with the drive lever member for pivotal movement of the lever member about the selected fulcrum to vary the length of the moment arm of the lever member to operate either at a high mechanical power advantage or at a high speed movement for fast opening of the hopper doors.
 6. In a hopper car having a pair of pivoted hopper doors, a door operating lever mechanism for opening and closing said doors comprising: a lever assembly including longitudinally spaced lever members and a connecting drive member, said lever assembly comprising a longitudinally extending force transmitting means and first lever means having upper portions pivotally connected with said connecting drive member and having lower portions connecting with said force transmitting means, second lever means having upper portions pivotally connected to the vehicle and having lower portions connecting with said force transmitting means, door arm means pivotally connected with the doors and to the lower portions of said first and second lever means, and lever pivot means being mounted on the car and connecting with each of the first and second lever means for accommodating pivotal movement thereof, the buff and draft forces developed in the force transmitting means being offset by the forces developed in the connecting drive member.
 7. The invention according to claim 6, and a fixed fulcrum member mounted on the car below the pivot means of the first lever means, said first lever means in pivoting between outboard and inboard direction being fulcrumed about the fulcrum member whereby a high mechanical power moment arm is developed between the drive means moving the first lever means upon initial opening of the door means and whereby when the door arm means moves past center to the door unlocking position, the first lever means fulcrums about its pivot means to develop a longer moment arm between the door arm means and the pivot means of the first lever means for quick travel gravity opening of the door means.
 8. A hopper car having pivoted hopper doors and a mechanism for opening and closing said doors comprising: longitudinally spaced lever means for applying a mechanical power advantage to the doors to open same, drive link means being reciprocally mounted for movement in a longitudinal direction and operatively connected with said lever means for operation thereof, linkage operating means operatively connected with said drive link means for reciprocating the latter, and longitudinally extending force transmitting means being connected with said lever means and being connected with said hopper doors and being spaced below said drive link means whereby forces developed in the force transmitting means would be offset by forces developed in the drive link means.
 9. The invention according to claim 8, and said linkage operating means comprising a scissors mechanism operatively connected with said drive link means for reciprocating the latter and a rotatable reversely threaded shaft means being operatively connected with and operative upon said scissors mechanism for extending and collapsing same to reciprocate the drive means.
 10. The invention according to claim 8, and lost motion connection means connecting with said lever means and with said drive link means permitting lost motion movement of the drive link means upon initial operation of the linkage operating means resulting in delayed contact between the drive link means and the lever means for movement of the lever means.
 11. The invention according to claim 8, and said linkage operating means comprising extendable means operatively connected with the drive link means and extendable in a longitudinal direction for moving the drive link means in a longitudinal direction, and threaded shaft means for contracting and expanding such extendable means being operatively connected with and operative upon said extendable means attendant to movement of said drive link means.
 12. A hopper car having pivoted hopper doors and a mechanism for opening and closing said doors comprising: longitudinally spaced lever means for applying a mechanical power advantage to the doors to open same, drive link means being reciprocally mounted for mOvement in a longitudinal direction and operatively connected with said lever means for operation thereof, linkage operating means operatively connected with said drive link means for reciprocating the latter, and lost motion connection means connecting with said lever means and with said drive link means permitting lost motion movement of the drive link means upon initial operation of the linkage operating means resulting in delayed contact between the drive link means and the lever means for movement of the lever means.
 13. The invention according to claim 12, and said lever means including a first lever member connected with said drive link means and a second lever member connected with said first lever member, said second lever member multiplying the mechanical effect of the first lever member and the first lever member multiplying the mechanical effect of the drive link means.
 14. The invention according to claim 13, and said second lever member including first and second fulcrums spaced vertically from one another and selectively engageable with the second lever member for pivotal movement of the second lever member about the selected fulcrum to vary the length of the moment arm of the second lever member to operate either at a high mechanical power advantage or at a high speed movement for fast opening of the hopper doors. 